Multiple terminal block



Dec. 6, 1955 J. GORDON MULTIPLE TERMINAL BLOCK Filed Dec. 17 1951 Juofgewu fnuenz f James G Ora 071 United States Patent M MULTIPLE TERMINAL BLOCK James Gordon, Chicago, Ill.

Application December 17, 1951, Serial No. 262,023

2 Claims. (Cl. 339-198) This invention relates to multiple terminal block suitable for use in wiring electrical apparatus such as switch boards, control circuits, test circuits, and the like.

In general, the invention aims to provide a multiple terminal block in which the individual sections carry integral means for simply and expeditiously interlocking them to provide a composite block assembly, eliminating any necessity for extraneous fastening members for securing the sections together, while at the same time multiple terminal blocks of varying sizes may be provided.

These and other objects and advantages will be apparent from the following description, taken together with the accompanying drawings, of an illustrative embodiment of the invention, and in which drawings Figure 1 is a plan view of a multiple terminal block embodying the present invention;

Figure 2 is an enlarged end view of the right-hand end of Fig. 1, partially in section;

Figure 3 is a perspective view, on the scale of Fig. 2, of an individual section; and

Figure 4 is a view of the opposite face of Fig. 3, on a reduced scale, and being also a left-hand end view of the structure of Fig. 1; and

Figure 5 is a partial section on the line 55 of Fig. 4.

Referring in detail to the illustrative construction shown in the drawings, and turning first to Fig. 3, the present invention provides an individual block section 11 which may be formed of insulating material such as a phenolic condensation product, hard natural or synthetic rubber or the like, and molded under the influence of heat and pressure to the desired shape for example here shown.

The block 11, is, as seen, L-shape, the foot of which provides a platform portion 12 and the leg of which provides a barrier portion 13 arising from the platform portion at one side thereof and along which side it extends throughout. In this instance, the platform portion 12 has built up thereon centrally thereof, a terminal mounting portion 14.

In accordance with the present invention, on the short vertical face 15 of the block section 11 are formed integral interlocking formations such as the two dove-tail tongues 16, these being dove-tail in that they are wider at their outer edges 17 than at the point 18 where they join the body of the block section. Since there are two of these dove-tail tongues arranged in parallel, they form between them a dove-tail groove 19, which is advantageously corresponding in width to the dove-tail tongue 16. These tongues 16, as shown, desirably extend throughout the height of the wall 15, except for an undercut 20 which thus elevates the lower ends of the tongues 16 slightly above the bottom margins 21 of the block section. The tongues 16 desirably extend upwardly along the edge of the terminal seating portion 14 of the block section and to be flush at their upper ends with the terminal seating portion.

Still further in accordance with the present invention, on the opposite face of the block section 11, and as seen 2,726,375 Patented Dec. 6, 1955 in the views of Figs. 1 and 4, the block section 11 has on this opposite face 22 a pair of dove-tail grooves 23 extending upwardly into the face 22 from the undercut portion of the block to a distance corresponding to the length of the dove-tail tongues 16, and in other respects corresponding to other dimensions thereof, so as to receive tongues 16 on another block section identical with the one shown in Fig. 3.

For purposes of a tight holding action, when a plurality of the block sections 11 are secured together to form multiple terminal block as shown in Fig. 1, either the tongues or the grooves, may be slightly tapered to provide a wedging action when they are interengaged. In such interengagement it will be observed that the portion 24 between the dove-tail grooves 23 itself forms a dove-tail tongue 24 which is received in the corresponding dove-tail groove 19 formed on the other face of the block between the tongues 16. Here a groove 23 is shown having approximately one-half the length of its back wall slightly tapered at 23a.

The upstanding barrier portion 13 of each block section forms a barrier or partition between the individual block sections when they are assembled together to form a multiple block as in Fig. 1, and it will be apparent that two block sections or substantially any number of block sections may be thus readily assembled together to form' a multiple terminal block for the electrical purposes for which such terminal blocks are provided.

For such electrical purposes as here illustrated, metallic terminal members are carried by each of the block sections 11 and as here shown a pair of binding posts. In this instance an integral rod-like metallic member 25, bent to U-shape, is shown having its bight portion 26 embedded in the platform portion 12 of the insulating block during the molding operation, the outer ends 25a of the metal member 25 projecting upwardly through the portion 14 and parallel with but spaced from the upstanding barrier portion 13, to provide binding posts, the latter being threaded as at 27 so that clamping nuts (not shown) may be threadedly secured thereon to attach circuit or current conducting wires in use. For security of attachment, metal washers 28 may be embedded in the block portion 14 at the base of each of the binding posts 25a.

For attachment of the multiple block assembly to any suitable support, which need not be here shown, each block section may have a through-passage 29 extending through the barrier portion 13 from the upper edge thereof and through the bottom face of the block at the cut-out 20. To limit passage of fastening screws therethrough the through-passages 29 may be counterbored as at 30 to provide seats for the heads of the screws and contribute to the holding action thereof. As seen from the drawing, the barrier portion 13 is advantageously laterally enlarged as by a semicylindrical bay 31 to provide one wall of the through-passage 29, and this bay 31 advantageously occurs centrally between the binding posts 25a thus conserving space without sacrificing efficiency.

Smaller holes 32 in the upper edges of the barriers 13 at their outer corners may provide openings to receive attaching screws for a partial closure for the block assembly which may include an identification strip for the circuits being dealt with, but which need not be here further shown and described since it forms no essential part of the present invention.

The invention is not intended to be limited to the precise details of construction shown for purposes of illustration and such changes may be made as fall within the scope of the appended claims without departing therefrom.

The invention having been described, what is here claimed is:

1. In a multiple terminal block embodying a plurality of block sections each section including a platform portion for mounting a pair of terminals therein, a plurality of dovetail tongues on a face of the section and a corresponding plurality of dovetail grooves on the opposite face of the section one opposite each tongue, that improvement wherein a portion only of the back wall of each groove is tapered by an inclination beginning approximately one-half of the length of the groove and from there inclined toward the face of the corresponding tongue on the adjoining section, the bottom face of each block section being undercut intermediately of the margins of the section between which said tongues and grooves are located and the tongues and grooves extending upwardly from said undercut, whereby the effect of said inclination upon the tongues received in said grooves is brought into play at the end only of relative movement of the tongues and grooves to lock the sections together.

2. In a multiple block of the class described embodying a plurality of block sections, one having a dovetail groove for receiving a dovetail tongue on an adjoining section, that improvement wherein a portion only of the back wall of the groove is tapered by an inclination beginning approximately one-half of the length of the groove and from there inclined toward the face of the corresponding tongue on the adjoining section, the remainder of the face of said back wall being parallel to the contiguous face of the tongue received therein, whereby the effect of said inclination upon the tongue is brought into play at the end only of relative movement of the tongue and groove by a final wedging action to lock the sections together while avoiding strains on the tongue and permitting normal tolerances.

References Cited in the file of this patent UNITED STATES PATENTS 509,364 Coffeen Nov. 28, 1893 835,211 Atkinson Nov. 6, 1906 1,072,523 Steinberger Sept. 9, 1913 1,159,567 Burton Nov. 9, 1915 1,936,963 Dutzmann Nov. 28, 1933 2,081,100 Blackeslee May 18, 1937 FOREIGN PATENTS 214,988 Switzerland Aug. 16, 1941 357,171 Great Britain Sept. 10, 1931 680,499 Germany Aug. 30, 1939 44,715 France Apr. 6, 1935 (1st Addition to No. 763,872) 

